In industrial measurements technology, especially in automation, and process control, technology, regularly applied are apparatuses, which, in the running of a process, measure process variables by means of sensors or adjust control variables by means of actuators. Such apparatuses ascertain, for example, pressure, flow, e.g. flow rate, fill level, dielectric constant, interface locations, temperature or some other physical and/or chemical process quantity as a process variable in the running of a process. Available from the assignee are, for example, such apparatuses in the form of field devices under the marks, Cerabar, Deltabar, Deltapilot, Promass, Levelflex, Micropilot, Prosonic, Soliphant, Liquiphant, Easytemp, which serve primarily to determine and/or to monitor at least one of the above referred to, process variables of a medium in a container.
A commonality of all of the above mentioned apparatuses, or field devices, is that, from the process variables registered by the sensors, a measured value is ascertained and evaluated by means of an electronics connected after the sensor. This electronics is, most often, so matched to the corresponding measuring requirements and to the process variable to be measured, that, for each sensor principle, for each process variable to be measured, and for each type of measuring performance, a special electronics must be developed. The signal processing function near to the sensor is, most often, embodied as an ASIC (Application Specific Integrated Circuit), which often is produced in large piece numbers. Another solution is to provide field devices with different measurement accuracy standards, a uniform electronics and maximum measuring performance and to activate or deactivate particular functionalities e.g. per software.
Disadvantageous in these electronics is that the costs for the electronics are often not proportional to the required measuring performance and no modularity is provided.